Team Fortress 2 Trailer 2 by Valve Software, released via. Steam on August 31st, 2006. Original download page
A longer trailer then the first, it has short scene segments detailing a class feature/short montage for 7 of the 9 classes. The medic is left out - only appearing in a cameo behind a box at 00:01:51, likely due to the changes in his abilities, with the healing gun and Ubercharge features not present at the time the trailer was made. The pyro lacks a scene, although is killed several times during the video.
It also interestingly has old models and content which were changed before release - including an old model for the Soldier's Rocket Launcher, the Demoman making use of MIRV (stick) grenades which were removed, the scout using a nail gun (later replaced by a pistol, the nail gun concept being used for the medic) and seen with a submachinegun (given to the sniper for the final game).
The map used, 2Fort, also underwent changes before release, adding a bridge over the middle path and other cosmetic differences, such as the main supply room (the Red one being see in the Engineer scene) having a large door instead of two smaller ones.
The video also contains no voices, which were likely not recorded by the time. Instead, listen out for the whilheim scream, and some old typical voices from previous Valve games used as placeholders.